Restrictor swivel for folding wing aircraft



May 23, 1950 A. c. NEWMAN ET AL yRESTRICTOR SWIVEL FOR FOLDING WINGAIRCRAFT 2 Sheets-Sheet 1 Filed June 2, 1947 INVENTORS Arnold C. NewmanJohn W. Woodward ATTORNEY y 3, 1950 A. c. NEWMAN ET AL 2,508,647

' RESTRICTOR SWIVEL FOR FOLDINGWING AIRCRAFT Filed June 2, 1947 2Sheets-Sheet 2 5 4.8 To FO D |2OA I26A 63 64 40A IOSA ||4A Fi 6 6 40A406 6 80 F I IOBAi 40 l 408 l L KR W 5 7 I06 EH! pf 72 E QLM -W 82 k\\LNVY- kink 79 7,0 86 LOB 8 I00 98 [02 2B 7 1 mfluu$ /4 80 I Fi 5 H65 HOBI IZIBSBB INVENTORS- 77 If 7 Arnold C- Newman I John w. Woodward 2 n46I066 '4 4flFw w Fig. 1 ATTORNEY Patented May 23, 1950 Rnsrmo'roR SWIVELFOR FOLDING WING AIRCRAFT Arnold G. Newman and John W. .Woodward.Stratford, Conn, assignors to United Aircraft Corporation, EastHardford, Conn,

' tion of Delaware a corpora- Application June 2, 1947, Serial Na.751,844

' 6 Claims. (01. 244-49) This invention relates to-aircraft such, forexample, as are commonly based on aircraft carrying vessels, in whichthe wings, Or outer panels thereof, have cordwise hinges and are movedbetween folded and extended positions by hydraulically actuatedmechanism.

In the use of aircraft-of this type, for example, in the operation of acarrier based fleet of fighter airplanes, it is often extremelyimportant to be able to unfold the wings in the shortest possible timeas each airplane is readied for flight; and likewise when the planes arecomin in from a flight in rapid succession it is important to be able tofold thewings and geteach plane off the runway quickly following landingto make room for the next incoming plane It is'an object of thisinvention to provide an improved foldablewing aircra-ft in which thetime required for folding and extending the wings is materiallyshortened; and more particularly to provide a folding wing actuatingmechanism for an airplane of this type whichmoves the movable wingsectio'nthrough the major part of its path of movement at a high rate ofspeedand-decelcrates itto permit itto come to rest gently at the end ofits movement:

Another object of thein-vention-is to providean improved restrictorvalve having its movable member operatively connected to the movablesection of the airplane wing and controlling the flow of fluid to thewingactuatin'gstrut.

A further object of the invention is to provide an improvedrestrictor-swivel inthe hinge for the foldable section of an airplanewing having; improved fluid' controlling mechanism therein for governingthe flow of fluid tothe'hydraulic wing actuating strut.

These and other'objeots of the" invention will be hereinafter pointedout or will become ap'- parent from'th'e following'detailed descriptionof one embodiment'of theinventionwhich" has been shown for purpose ofillustration in the accompanyingdrawings.

Inthes e drawings, 7

Fig, 1 is a fragmentary-view of an airplane having outer folding wingpanels, the view being taken looking aft at the left-hand wing with aconsiderable portion of the outer wing panel broken away;

Fig. 2 is a perspective view of a restrictor-swivel valve forcontrolling the flow of hydraulic fluid to the wing actuatingstrut, themovable valve member being shown in: the position it occupies when thewing panel is extended;

Fig. 3 is a detail: View of the movable member of the valve of Fig.2; VV I Fig. 4 is an endview of the movable valve member ofFig .3;

Fig. 5 is a bottom plan View of the valve of Fig. 2;- I g Fig. 6 isatrue sectional view on line 66 of Fig. 5; V

Fig. 7 is a sectionalview taken on line 'l1- of Fig. 5 showing the valvemember inthe posi; tion it occupies when the outer wing panel" is;folded; and.

Fig. 8 is a' diagrammatic view of the hydraulic system for effecting thefolding and unfolding of the outer wingpanel...

Referring to Fig. .l', the numeral It] indicates the fuselage of an.airplane having. a Wing com:- prising an inner panel l2 rigidly.attached tot-he fuselage and an outeripanel. M which is, foldableupwardly from the horizontal. position shown about a cordwise hingeline.l6: through. an angle of into a folded position in which its tipliesover the fuselage. While only the left-hand wing of the airplane hasbeen shown herein itwill be understood that thetwowings are identical inconstruction except for their right and left-handline 28.. Fluidbypassing valve; 24flqwsthrough' aline 28 into a fluid return line 30which discharges into the reservoir 22. Fluidunder pressure in line 26passes through a manually controlled two-way selector valve; 32.; whichconnects the pressure lineZB to one of two fluid. lines 34, 36,depending upon the position of the valve, and simultaneously connectsthe other line ,to' drain through a fluid line 38.- I'n the position. ofvalve 32 shown in Fig-.8 the pressure line 26 is connected to line 36,and linentd is connected to drain. The fluid lines 3i and? 3:31communicate through separate fluid passages in a. restrict on swivelvalve 40, hereinafter more fully described;

and fluid lines 42 and A4 With fluid'cham-bers .46

and 48 on opposite'sides of a piston 50 of a wing.-

wing panels with the axis of its movable member lying in hinge line I6.It will be evident as the description proceeds that this valve is notnecessarily located in the hinge line but could equally well be located,for example, in the inner wing panel I2 remote from the hinge line andbe operated by suitable linkage connected with the folding outer wingpanel I4.

The restrictor-swivel valve 40, as shown most clearly in Fig. 5 and thesections taken thereon, includes two stationary valve bodies 66a and661;, which are basically the same except for their left and rightrelationship, and a swivel bolt 460, shown in detail in Fig. 3, havingintegral flow controlling valve portions 56 and 58 which cooperaterespectively with the valve bodies 66a and 66b to control the rate offlow of fluid through these valve bodies and through fluid lines 62 and46 leading to the wing strut.

The swivel bolt 460 in addition to the valve stem portion thereof whichcarries the valve portions 56 and 58 has an external eccentric hoodportion 66 provided with diverging fluid passages BI and 62 terminatingin threaded connections 63 and 64 into which the rigid fluid lines 42.and 44 are screw threaded. The axis of rotation of the swivel bolt, asherein shown, is coincident with the hinge line I6 of the wing panel.Accordingly, since the rigid fluid lines 62 and 4 1 are fixed in theouter wing panel, the swivel bolt 660 is moved through an identicalangle as the outer wing panel swings about its hinge line I6. PassagesBI and 62 communicate with parallel channels 66 and 68 which extendalong the stem of swivel bolt 46c and are closed off at their endsremote from the hood 60 by screw threaded plugs, one of which is shownat Ill in Fig. 3.

The valve portions 56 and 56 are generally cylindrical and are sealedoff by O-ring packings (not shown) located in grooves I2, i l and 16which engage the inner bore of the valve housing in a well known mannerto prevent fluid communications along the valve stem.

The cylindrical valve portions 56 and 58 have centrally formedeccentric, or cam, portions 18 and 19 respectively which are angularlyrelated about the axis of the stem as indicated in Fig. 3. These camportions I8 and I9 are in effect wide, generally flat-bottom groovesformed in the cylindrical valve portions which cooperate with the flatfaces of pistons 80 having their threaded shanks 82 adjustable in plugs64 threaded into the valve housing. Lock nuts 86 are provided externallyof the plugs 84 on the stems 62 for locking the pistons 86 in a selectedposition of adjustment relative to the cam surfaces. The grooves formedby the cam portions 18 and 19 in the two valve portions are identicalexcept for position and further include a small central relief groove 88extending around the cut away periphery of the valve portion which formsthe cam. The cam portions 18 and 19 communicate through transversepassages 90 and 92 with channels 66 and 68 respectively. Also at a pointslightly spaced around the periphery of the valve portion from thepassages 90 and 92 a series of holes or depressions 94 arranged alongthe length of the valve portion, herein three, are provided in thecylindrical valve surface. Nearer the end of groove 88 in the camportion a similar hole 66 is provided adjacent holes 94 and this latterhole communicates with the groove 88 of its respective cam portion. Thepurpose of the holes 94, 96 are hereinafter explained. The swivel bolt460 is retained in the valve housing by a series of balls 98 (Fig. 5)which are introduced through a passage I60 in the valve body 462) andoccupy complemental annular grooves I02 and I66 in the housing and valvestem respectively. The hole I66, following insertion of the balls, isclosed by a cap screw I06.

Referring to Figs. 5 and 6, the valve body 4611. is provided with athreaded fluid connection I66a communicating with a passage IIIla in thevalve body which intersects the valve stem receiving passage in thehousing in the planes of the cam portion I8. A second passage II2aparallel with passage W811 and lying in the same transverse plane isprovided on the opposite side of the axis of the valve stem. The outerend of passage I I2a is closed by a plug 4a, and the inner end ofpassage II2a, like passage IIfla, intersects the valve. stem receivingpassage in the housing in the planes of cam portion 18. A transversepassage I I6a of somewhat larger diameter intersects the passages IIIla,HM, and has its open end closed by a plug 8a threaded into the valvehousing. The plug I Illa has a passage I260; which is aligned withpassage Ba and also has an axial passage I22a which is smaller thanpassage II6a in the housing and which intersects passage IZIla. Theinner end of plug IISa is recessed to provide a seat for a ball checkvalve I2 la which is normally held against the seat by a spring I26awhich bears against the ball at one end and against the housing at itsother end.

Valve body 4% is identical with the valve body 46a above describedexcept for the reversal in position of the parts, and the correspondingparts have been given like numerals identified by the letter 17. It willbe understood that the passage Hill) and H21) of valve body 461)communicate with the valve portion 58 on the valve stem 460.

In operation, the outer wing panel It as it swings through its 135 ofangular movement between its folded and extended positions moves theswivel bolt 400 with it, thus moving the fluid restricting valveportions 56 and 58 relative to the faces of pistons into such positionsthat the cam in the passage supplying fluid to wing strut 5| allows freepassage of fluid to the wing actuating strut throughout the entiremovement while the cam in the passage returning fluid from strut 5I atfirst permits free return of fluid from the strut and then, as themovable wing panel approaches the end of its arc, restricts the path ofthe returning fluid between the cam surface and the face of theadjustable piston 80. It will be evident that the valve portion 56 invalve body 40a controls the restriction of the return fluid during theextending movement of the wing panel while valve portion 58 in valvebody 461) controls the restriction of the return fluid during foldingmovement of the wing panel.

Fig. 6 shows in full lines the position of the swivel bolt 460 relativeto the passages in' the valve body 40a when the'outer wing panel is inthe extended position shown in Fig. 1. To fold the panel It the selectorvalve 32 is moved from the position shown in Fig. 8 to admit fluid underpressure from line 26 through line 36 to the 7 body 46a of the valve.This fluid entering atthe connection I68a flows through passage IZilaand, since the chamber formed by passage Ilfla is sealed off by thecylindrical part of valve portion 56 which abuts the face of piston 86,the fluid passes through check valve I24a into passage IIZa, about thecam portion I8, and by Way of passage 90 and channel 66 in thestemofswivel 'bolt 460 into the hood portion 66; The fluid then I newsthrough passage 51 and connection 53 to the fluid one 42 and finallyinto chamber 46 of the wing strut, causing the piston 50 of this strutto actuate the linkage in a direction to raise the panel l4 ihto foldedposition.

Throughout this 135 folding movement of the can porn -n '18 channel litas above described. During the latter part of the folding movement thepart of valve portion 56 which is concentric with the swivel boltwillhave moved away from the face of piston 80 so as to allow fluid to flowfrom chamber l Illa directly past the piston face and out through thepasage 8E and channel 66. This will be evident from the dotted lineposition of the cam l8 shown in Fig. 6, which indicates the position ofthe cam at the end of the folding movement.

During the above described movement of cam 73, cam 19 has been movingfrom the dotted position counterclockwise into the full line position ofthis cam shown in Fig. 7. It will be noted that with cam 79 in thedotted position shown in Fig. '1, which represents the position of thiscam when the wing panel is in extended position, cam 79 permits freeflow of fluid returning from wing strut chamber as through passages 45,64, 62, 63 and 92, into passages llilb, [2%, connection H581) andpassage 3 However, near the end of the 135 folding movement of swivelbolt 48c, the flow of fluid is gradually cut on" by cam portion l9 andpiston 8i) and, since the fluid in chamber 2b cannot pass through checkvalve l 24b, as the swivel valve approaches folded panel position (inwhich the cam H5 is in its full line position in Fig. 7) flowpractically ceases and the wing is brought gently to a stop in foldedposition. It is during this final throttling action of the valve portionthat the transverse depressions 99, as function. These depressions serveto create a turbulence in the hydraulic fluid as the hydraulic fluidflows past them and, other conditions remaining constant, turbulentfluid does not flow through an orifice as readily as non-turbulentfluid. This helps to make the transition from the condition of flow tothe condition of no flow past the restricting surfaces more gradual andsmooth.

The operation of the swivel-restrictor valve during the extendingmovement is the same as that above described except that the fluid flowto the wing strut chamber 46 through valve body 401) is unrestricted byvalve portion 53 and the restriction takes place near the end of the eX-tending movement between the face of piston 80 and valve portion 56. Thefully restricted position of valve portion 56 is shown in full lines inFig. 6.

It will be evident that as a result of this invention a combinedrestrictor-swivel valve has been provided which eliminates the separaterestrictors heretofore required in the hydraulic lines with a consequentreduction in weight while greater wing folding efficiency is gained.

With the prior fixed, or constant, restrictors the rate of movement ofthe movable wing sections throughout their entire range of angular move-(i this angular movement the flow and out through passage 9i) and mentwas limited to the slow speed at which it was permissible for the"sections to be moving at the end of their folding-or extendingmovements. It will be evident that by providing variable restrictorswhich are operated in synchronism with the angular movements of thewing-sections, it has been made possible to move the wing sections atthe desired slow speed at the ends of their angular movements whilegreatly accelerating their movements throughout the major portion of the135 angular path through which they move. As a result the time requiredto get an airplane into or out of action has been very materiallyreduced. g I 7 It will further be evident that by thecombinedrestrictor-swivel valve construction of this invention these desirableresists have been obtained while at the same time providing a'sirnplified and considerably lighter hydraulic system for the actuationof the movablewing sections.

While only one embodiment has been shown herein for the purpose of fullydisclosing the invention so that others may understand and obtain theadvantages of the invention in practice, it

will be understood that various changes may be' made in the constructionand arrangement "of the parts without departing from the scope of theinvention as defined in the claims. For example, the particular valvestructure illustrates only one of numerous ways to construct a variablerestrictor valve, and the valve could obviously be locatedon the fixedstructure ofthe airplane re: mote from the hinge line of the wingja'ndb'e operative'ly connected with the movable wing panel, or alternativelybe located on 'themovable wing panel and be operativly connected'withthe relatively fixed airplane structure.

We 'claim:

1. In an airplane having a fuselage, a 'wing including an inboardpanelrigidly mounted on said fuselage and a foldable outboard panelhaving a hinged support in the extremity of said inboard panel, meansfor folding and unfolding said outer panel including a hydraulic strut,means for supplying liquid u'nder pressure to said strut including fluidlines, means for controlling 'thesupply of fluid to said strut includinga valve having relatively stationary "and movable parts, one of which iscarried by said outer panel, and means for moving said outer panel atdifferent velocities in different parts of its range of movementincluding cooperating means on said parts for varying the rate of fluidflow through said lines to said valve i different angular positions ofsaid outer panel.

2. In an airplane having a fuselage, a wing including an inboard panelrigidly mounted on said fuselage and a foldable outboard panel having ahinged support in the extremity of said inboard panel, means for foldingand unfolding said outer panel including a hydraulic strut, means forsupplying a liquid under pressure to said strut including fluid lines,means for controlling the supply of fluid to said strut including avalve located in the hinge lines of said outer panel having relativelystationary and movable parts, one of which is carried by said outerpanel and means for moving said outer panel at difierent velocities indifferent parts of its range of movement including cooperating liquidthrottling elements on said valve parts for varying the rate of fluidflow through said lines to said strut.

3. In an airplane having a fuselage, a wing including an inboard panelrigidly mounted on said fuselage and a foldable outboard panel having ahinged support at the extremity of said inboard panel, means for foldingand unfolding said outer panel including a hydraulic strut, fluidconnections for said strut, a selector valve for reversing the flow offluid in said connections and swinging said outer panel in oppositedirections, a restrictor-swivel valve in the hinge line of said outerpanel having relatively stationary and movable elements, one of whichelements is operatively connected to said outer panel, saidrestrictorswivel valve having passages therein forming a part of saidfluid connections, and means on said movable element of said lattervalve for restricting the rate of fluid flow in said passages only whensaid outer panel approaches said folded or extended positions thereof.

4. In an airplane having a fuselage, a wing including an inboard panelrigidly mounted on said fuselage and a foldable outboard panel having ahinged support on the extremity of said inboard panel, hydraulicallyoperated means including a hydraulic motor for swinging said outboardpanel between extended and folded positions, a source of liquid underpressure, means for connecting said motor to said liquid source, a fluidrestrictor valve in said connecting means comprising a stationaryelement carried by said inboard panel at said hinged support and arotatable element having its axis of rotation coincident with the axisof said hinged support, means for operatively connecting said rotatableelement with said outer panel, and cam means on said rotatable element.providing for free liquid flow to said motor during the major portion ofthe range of movement of said movable panel and restricting said flow assaid movable panel approaches its extended and folded positions.

5. In an airplane having a fuselage, a wing including an inboard panelrigidly mounted on said fuselage and a foldable outboard panel having ahinged support on the extremity of said inboard panel, hydraulicallyoperated means including a hydraulic motor for swinging said outer panelbetween its extended and folded positions, a source of fluid pressure,fluid lines connecting said motor with said source of pressure and withdrain, a restrictor-swivel valve in said fluid lines having the axis ofits swivel located in the hinge line of said hinged support forcontrolling the flow of fluid in said lines as said outer panelapproaches its extended and folded positions, said valve including avalve body carried by said inboard panel having passage means thereinfor connection to said fluid lines and a movable element having a pairof cams thereon, one of which is located in and controls each of saidpassage means, and means for operatively connecting said movable valveelement with said outer panel.

6. In an airplane having a fuselage, a wing including an inboard panelmounted on said fuselage and a foldable outboard panel having a hingedsupport at the extremity of said inboard panel, means for folding andunfolding said outer panel including a hydraulic strut, fluidconnections for said strut, a selector valve for reversing REFERENCESCITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,064,847 Mills June 17, 19131,329,881 Bloom Feb. 3, 1920 2,162,233 Schoenberger June 13, 19392,284,994 Stuckenholt June 2, 1942 2,289,224 Swanson et al. July '7,1942 2,290,850 Umschwief July 21, 1942 2,358,988 Magrum Sept. 26, 19442,376,636 Thompson May 22, 1945 FOREIGN PATENTS Number Country Date476,590 Great Britain Dec. 13, 1937

